darkangelz: Not that unlikely. Surviving Mars did get released here recently. If i were to bet, i'd say its more unlikely due to the price point a "complete edition" would go for here. Unless they'd go for a complet'ish edition + afew themed sets of DLC packed together.
Grargar: Surviving Mars is not developed by Paradox, though. Any Paradox-developed game released here has been update and DLC-complete, a status not shared by Crusader Kings 2 (along with Europa Universalis IV, Hearts of Iron IV and Stellaris).
Yeah, there are two Paradoxes: Paradox Development Studio is a developer and Paradox Interactive is the publisher. All PDS games are published by PI, but PI also publishes other games. The core Paradox games, formerly known for being extremely difficult to learn and targeted to hardcore history/strategy fans, and now infamous for the DLC bloat, are the ones developed by PDS.
Crosmando: Hopefully a "complete edition" of CK2 comes out soon and gets released on GOG.
mystral: That's very unlikely. Paradox have said outright they wouldn't consider stopping the DLC spam until they felt like making a sequel instead, and that they wouldn't start on CK 3 unless they felt it could be a big enough change compared to CK 2 (i.e. new engine among other things most likely).
As for it ever coming to GOG, I'd say that's even more unlikely. They've given up on DRM-free and become wedded to Steam after CK 2's release, because according to them the DRM-free version they released alongside the Steam one didn't have enough sales (around 5% IIRC) to make it worthwhile. It wasn't that surprising considering said DRM-free version was exclusive to Gamersgate, which isn't exactly the most popular store ever, but whatever.
Anyway, ever since then, they've pretty much tied the multiplayer and modding of all their games to Steamworks, and I'd guess Paradox wouldn't consider it worthwhile to change that and do a Galaxy version instead.
Not only that: if someone even dares to suggest to have a DRM version of a Paradox game in the Paradox community forums, they will be accused by the majority of other users of ludites at best, and of pirates at worst.